1. Field of the Invention:
This invention relates to a rotary ring for spinning machinery, such as ring spinning machines, ring twisting machines, etc., particularly, a rotary ring for spinning machinery of such type that its ring-shaped rotator is turned by frictional resistance with a traveller.
2. Description of Prior Art:
As to rotary rings of this kind, there have been suggested, for example, a rotary ring of such type that a ring-shaped rotator is caused to lift by air pressure so as to realize a higher spindle speed of spinning machinery and to improve productivity and a rotary ring of such type that a ring is supported by bearings at its circumference. Additionally, FIG. 8 shows a rotary ring of a type wherein a sliding body (15) is interposed between a ring-shaped rotator (13) and a ring-shaped holder (14) and the ring-shaped rotator (13) is supported rotatably. This arrangement is set forth in Japanese Patent Application Publication Gazette No. 60-56807.
This rotary ring comprises a ring-shaped rotator having a ring-shaped flange at a top part thereof, a sliding wheel and a holder. The height of the sliding surface of a sliding part is made 1/3-3/4 of the total height of a rotary ring so as to make rotation during spinning smooth and to reduce partial lifting.
Another rotary ring type is set forth in Japanese Laid Open Patent Application Gazette No. 48-77130. This rotary ring limits the weight (W) of its rotary ring to within the scope obtained by the following formula as a function of the ring diameter (inside diameter of ring-shaped flange): EQU 0.01050-0.40+70.gtoreq.W.gtoreq.0.01050-0.40+50
(W is the weight (in grams) of the rotary ring and 0 is the diameter (in millimeters of the ring).
This rotary ring, even if the spindle is turned at a speed higher than usual, involves the least frictional resistance between the rotary ring and a seating ring which supports the rotary ring. Thus, the rotary ring turns effectively and smoothly, free from vibration.
However, rotary rings of these types in which a ring rotator turns by frictional force with a traveller raise the following problem.
In the case of the rotary ring shown in FIG. 8, if the sliding area between the ring-shaped rotation (13) and the sliding body (15) normal to the thrust (or axial direction is to much larger than the sliding area between the ring-shaped rotation (13) and the sliding body (15) radial direction, the frictional torque increases and rotation of the ring-shaped rotator is impeded and contact pressure increases. On the other hand, if the sliding area normal to the thrust direction is too much smaller than the sliding area normal to the radial direction, the sliding surface normal to the thrust direction is subject to greater wear. Also, if the weight of the ring-shaped rotator is too large, frictional force between the ring-shaped rotator and the sliding body becomes large, with the result that the number of revolutions required for the ring-shaped rotator cannot be obtained and fluffing occurs frequently. On the other hand, if the weight of the ring-shaped rotator is too light, frictional force between the ring-shaped rotator and the sliding body becomes too small, with the result that when a spindle is stopped, the ring-shaped rotator does not stop but continues to turn by inertia and a traveller turns as it follows the revolution of the ring-shaped rotator. This can cause snarls of spinning yarn and end breakage at re-starting.
For the rotary ring it is general practice to lighten the weight of a ring-shaped rotator so as to increase r.p.m. of the ring-shaped rotator. For lightening the weight of the ring-shaped rotator, thickness of a trunk part of the ring-shaped rotator is reduced or its height is reduced. However, the thickness of a trunk part of the ring-shaped rotator cannot be made too thin because the relation with the ring diameter must be taken into consideration. Also, a thin trunk part is apt to warp and therefore abnormal rotation of the ring-shaped rotator occurs. If the height of the ring-shaped rotator is reduced, fluctuation to a clearance between the ring-shaped rotator and the sliding body becomes large and setting of a proper clearance is made difficult.
An object of the present invention is to stabilize and make smooth the rotation of the ring-shaped rotator. Another object of the present invention is to provide a rotary ring which stabilizes sliding of a traveller and which is free from end breakage and abnormal wear.